Ixazomib and daratumumab without dexamethasone (I-Dara) in elderly frail RRMM patients: A multicenter phase 2 study (IFM 2018-02) of the Intergroupe Francophone du Myélome (IFM).
Authors: Xavier Leleu, Margaret Macro, Cyrille Touzeau, Clara Mariette, Salomon Manier, Sabine Brechignac, Laure Vincent, Benjamin Hebraud, Olivier Decaux, Samantha Schulmann, Caroline Lenoir, Pascal Godmer, Agathe Farge, Laure Peyro Saint Paul, Jean-Jacques Parienti
Journal: Journal of Clinical Oncology (2022)

8000 Background: Frail patients with multiple myeloma have an inferior outcome, especially in the relapse setting. This adverse prognosis is mainly related to a high discontinuation rate due to treatment (Tx) related adverse events. The aim of this phase 2 study is to evaluate efficacy and tolerability of Ixazomib-Daratumumab (I-Dara) without Dexamethasone in elderly frail patients with relapsed myeloma (RRMM) (NCT03757221). Methods: Ixa-Dara naïve RRMM patients received oral Ixazomib (4 mg: days 1, 8, 15), IV Daratumumab (16 mg/kg; days 1, 8, 15, 22, cycles 1-2; days 1, 15, cycles 3-6; days 1, cycles 7+) and IV Methylprednisolone before Daratumumab (100 mg at day 1, 8, cycle 1 and then 60 mg). They were enrolled after 1 or 2 prior therapy if their frailty score was ≥ 2 by IMWG score. The primary endpoint was ≥ very good partial response rate (VGPR) at one year. Secondary endpoints included ORR, PFS, OS &amp; toxicity according to NCI-CTCAE version 5. Results: Sixty-three patients were screened and 55 enrolled between 03/2018 and 09/2021. Patient were at first (n = 36) or second relapse (n = 19). Thirty-three patients (60%) were previously exposed to bortezomib, 37 (67%) were previously exposed to lenalidomide (Len) and 20 (36 %) were refractory to Len. Median age was 82 (72-93). All patients had a frailty score ≥2 and 13 (24 %) had a 3 or 4 frailty score. In 41 patients ISS at diagnosis was stage I (n = 11), II (n = 18) or III (n = 12). Seventeen (36%) patients harbored high-risk (HR) cytogenetic, including t(4;14) (n = 8) or del17p (n = 10). The median duration of Tx among 28 pts with ongoing Tx was 10 months [5-32] at data cutoff (February, 2)]. The median duration of Tx among 27 pts who stopped Tx was 6 months [0-18]: 18 had progressive disease. Nine patients died during the study: Daratumumab-related bronchospasm (D1C1); Ixazomib-related overdose (C2); sepsis (n = 4), progressive disease (n = 3). Regarding toxicity, 27 pts had a ≥grade 3 AE (49%). The most common grade 3-4 toxicities were thrombocytopenia (n = 9), other cytopenias (n = 4), infection (n = 8), hypertension (n = 3) and gastrointestinal disorders (n = 3). Fourteen out of 28 were SAE including 5 infections, 1 bronchospasm, 1 acute respiratory failure and 2 ixazomib overdoses. Overall response rate, including minimal response, was 86 % with a ≥VGPR rate of 32 % in the whole group. In Len refractory patients the ORR was 82 % and ≥VGPR 41%, in HR cytogenetic patients ORR was 85 % and ≥VGPR 46%. With a median follow-up of 11.6 months median PFS is 16 months and median OS NR (76% estimated at one year). Conclusions: In this elderly frail population Ixa-Dara is a feasible combination with favorable efficacy profile even in Len refractory and HR cytogenetic patients. Early toxicity remains a concern in this population eventhough more manageable with Dara SC. Clinical trial information: NCT03757221.